Kamal Nath was first elected to the 7th Lok Sabha in 1980. He was re-elected to the 8th Lok Sabha in 1985, the 9th Lok Sabha in 1989, and the 10th Lok Sabha in 1991.

He was inducted into the Union Council of Ministers as Minister of Environment & Forests in June 1991. From 1995 to 1996 he served as union minister of State, Textiles (Independent Charge).

He was then elected to the 12th Lok Sabha in 1998 and the 13th Lok Sabha in 1999. From 2001 to 2004, he was the General Secretary of the INC. He was re-elected to the 14th Lok Sabha in the 2004 elections and served as Union Cabinet Minister of Commerce & Industry from 2004 to 2009.

On 16 May 2009 he again won the elections from his constituency for the 15th Lok Sabha and re-entered the Cabinet, this time as Union Minister for Road Transport and Highways. In 2011, as a result of a cabinet reshuffle Kamal Nath replaced Jaipal Reddy to take on his role as Minister of Urban Development. Jaipal replaced Murli Deora as minister of petroleum natural gas.

In October 2012, Nath was confirmed to the ministry of parliamentary affairs in addition to his current role as urban development minister.

In late 2012, Nath replaced Pranab Mukherjee to help the UPA government win a crucial debate on FDI retail. Nath also replaced rural development minister Jairam Ramesh as an ex-officio member of the Planning Commission in December 2012.